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Arjen Visser
04-12-2008, 10:07 AM
DDC stands for Dbvisit Standby Database Configuration file.

This is a Dbvisit Standby created text file which contains all the settings for each database.

There will be a DDC file for each database or instance that has Dbvisit Standby configured.

There will be 2 copies of every DDC file. One copy on the primary server and one copy on the standby server. Dbvisit Standby copies the DDC file automatically to the standby server. If any updates are made to the DDC file on the primary server, Dbvisit Standby will automatically update the DDC file on the standby server.

The DDC file contains all the necessary configuration information to keep the standby database up to date. The file(s) will be in the Dbvisit Standby install directory and has the format:
dbv_oracle_database.env
Where oracle_database is usually the name of the database (although this is not strictly necessary).

For RAC the name of the DDC file is:
dbv_instance_name.env

For multiple standby databases, each standby database must have a unique DDC file name.

The DDC file can be manually edited with any text editor and updated, but this should only be done on the primary server.
The updated DDC file will be automatically transferred to the standby server.
The DDC file can also be updated by using the dbvisit_setup program and choosing option 6. The advanced settings can only be updated by manually editing the DDC file.
If the DDC file on the standby server is edited and updated, then all updates will be lost the next time Dbvisit Standby is run on the primary server.

The DDC file also contains the settings for the Dbvisit Standby Archive log Management Module (AMM).

An example of the contents of the DDC (only partly shown):
################################################## #############################
# Dbvisit Standby Database technology
# Dbvisit Database configuration file.
# This file is automatically generated at setup,
# but can be modified.
#
# (C) Avisit Solutions Ltd.
# New Zealand
#
################################################## #############################
#================================================= =============================
# ==> Main generic settings. For explanations see >>>Explanation>>>
#================================================= =============================
[10 Generic Settings]
ORACLE_SID = w111g
ORACLE_HOME = /oracle/orabase/product/11.0/Db_1
OWNER = oracle
ORATAB = /etc/oratab
CP = /usr/bin/scp
RSH = /usr/bin/ssh
COMPRESS = dbvisit
UNCOMPRESS = dbvisit
ZIP_EXTENSION = .gz
SEND_HEARTBEAT_TIME24 = 0700
TMP = /usr/tmp
PATH = /usr/local/bin:/bin:/usr/bin:/usr/X11R6/bin:/usr/sbin:/sbin

#>>>Explanation>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
# ORACLE_SID - Name of Oracle Database.
# ORACLE_HOME - Optional. Specify the Oracle home for the database.
# OWNER - OS account that runs Dbvisit.
# ORATAB - Unix/Linux only. File that lists Oracle databases.
# CP - Copy method to transfer updates to the standby server.
# RSH - Remote shell method used by Dbvisit.
# COMPRESS - Compression method used (Dbvisit is internal method).
# UNCOMPRESS - Uncompression method used.
# ZIP_EXTENSION - Extension used by compression method.
# SEND_HEARTBEAT_TIME24 - Time the daily heartbeat alert (email) is be sent.
# TMP - Temp directory for Dbvisit temp and trace files.
# PATH - Path to the server environment.
#<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
#================================================= =============================
# ==> RAC settings. Only applies if using Oracle RAC.
#================================================= =============================
[15 RAC Settings]
RAC = N
RAC_TAKEOVER =
RAC_TAKEOVER_SID =
RAC_TAKEOVER_FORCE =
.....